I agree completely. I never did like the looks of the smooth centers that were on 2000 cars. Thankfully I never had to worry about purchasing the 2001 centers...
Good luck on the auction. You might also want to see what they would cost through GMPartsDirect.com
. If I get some time, I'll try and see if the caps have a P/N on them so you can look them up.
**EDIT** Forgot my car was in the garage, LOL. The only thing that the center caps read out on the inside for mine is the month/year when molded, Olay Plastics (manufacturer), GM J1, ISO, ABS+PC, 9594222, MOLD NO 337. And 9594222 isn't a valid GM partnumber.